Best manifold/downpipe for a IHI VF-14 Turbo
 

Hello everyone,
I've been doing as much research as I can, and I feel like at this point I've read just about every Miata related forum post that relates to this turbo, and I haven't been able to find too much. I've read that it "should" perform similarly to a gt2554, topping out at roughly 200ish HP (my target), and spooling at around 2500rpm. The thread I read indicated that this was his experiences with the turbo, which means he had a way to install it. I however haven't been able to find a single post or webpage talking about what manifold or downpipe to use. Would there be a way to use this turbo that doesn't involve completely custom fabricating everything? Would it be better to use a flyin miata style cast manifold, with some sort of adapter, or weld a t25 style flange to this turbo? Or would it just be better to forget this turbo, and go with the more widely used and supported gt2554 or gt2560?

The reason I'm looking into this is because I found a guy local to me selling a 1.6l miata engine, transmission, with this turbo and a manifold from a 1992 capri for $500 for everything, which in my mind seems like an amazing deal. Before pulling the trigger on it, I thought I'd get some opinions of some people from here, cause a lot of you guys are way more knowledgeable about this than me. I've been trying to learn as much as I can about cars, but I've never done any sort of performance mods before, so FI is pretty new to me.

Building around a cheap and or free turbo when you can not fabricate everything by hand is a very bad route to go.

No such manifold/downpipe exists
$500 for a shit 1.6 engine, a $100 5 speed, and a junk yard turbo is not a "deal".

if you are a noob at car modifications and turbos, you better have deep pockets or start learning quick.

it takes $5k to reliably turbo yourself, almost double if you pay others to do it. You got that kind of coin?

Ah I guess that makes sense. I'd look into fabrication but I don't have access to a TIG welder, and I'm not exactly the best at welding anyway. The guy is including a manifold with it, but says it likely wouldn't work for a miata without mods (he had the engine to put in a different vehicle, but it never ended up happening so he was going to sell it) I'll attach a picture, but it has the turbo facing the opposite way from what would be ideal. It's possible the turbo may be able to be flipped to face forward, but there would still be the exhaust to worry about.
https://cimg9.ibsrv.net/gimg/www.mia...64cb1af8e0.jpg

A mig welder works fine....

How exactly are you going to modify a cast iron manifold? Its imposibru.

one word. Foughgetaboutit

Yeah, looks like I'll probably reconsider on this turbo. Still though, at least based on what pops up around me I thought it seemed decent on the pricing, what would a 1.6l be worth? Before the only one's I've seen is one guy asking $600 for the engine, plus a few extras such as a starter and alternator (no transmission), and then there was a wrecking yard selling two engines (just the engine, nothing else) for $700 each. If there's somewhere that has engines for way cheaper, I'd love to hear about it haha.

Building a Miata for a turbo is much more than just the turbo itself, especially if your car came with a 1.6 to start with. If you're not welding, a cheap turbo that nobody uses is going to cost you more in the long run. Read more or start fabbing

whats wrong with your motor that you want to swap it?

if swapping, find a decent 1.8L engine, they swap over fairly easily, and have great performance benefits, with or without turbo. and cost not much more than getting another 1.6L

Wow well I planned that horribly, I wrote out a message/post, and when I moved my mouse to submit it, I somehow managed to jamb my thumb between my keyboard and mouse like a dumbass hitting a side button on my mouse that's programmed to the back button. It went back a page, and completely erased what I wrote. Just my luck lol

Anyway with that out of the way, I definitely know I'll need to upgrade a few other things in the car as well. I've heard the differentials aren't the most reliable. I do have standalone engine management, and an aftermarket clutch installed and taken care of though, so I'm slowly getting things prepared.

As for what's wrong with my motor, it's mainly just tired at 220k miles, plenty of oil leaks, idles wierdly due to what I think is a bad IAC valve, overall it probably could use a rebuild. And then I saw this set up parts come up, and was thinking maybe I could get a head start by getting an engine I could either use or learn to rebuild and then use, a trans to replace mine that gets stuck in reverse, and then the turbo was just icing on the cake (if there were only a way to use it lol). I know I could probably just rebuild my motor, but I'd rather not have the car down for several months, and plus my motor has the short nose crank (no wobble yet, but I've heard it can lead to some issues).

I was considering a 1.8 swap, but I'm not sure my engine management (MS2 PNP) would be compatible. It's still something I would be considering though, if the performance gains would definitely be worth it.

Sell the cars buy a 1.8 model. Then proceed. Or else spend more fixing this one.

PASS on that crap!

That manifold turbo setup is from a FWD Mazda. I had one similar that I installed in my previous 1995 Escort GT. Originally it was an IHI VJ-11 if I remember correctly. I used the cold side from a turbo Ford creating something that was likely similar to the VJ-14 if the parts weren't from one directly. Spool was fine even with crush bent 2.5" exhaust but power/torque fell off hard after 5500-6000 RPM but I was using piggyback spark/fuel with no dyno tuning, just best guess tuning with an extremely inexpensive setup 15-20 years ago.

Megasquirt PNP doesn't necessarily care what type of engine you're trying to control (aside from an NB2 w/ VVT) as long as it matches your year of car/chassis.

Sorry for not being back here for a few days, things have been extremely crazy lately. I've decided that there definitely would be better ways to go about this than getting that turbo and trying to make it work. When doing something like this, it's best to do it the right way.

I have seen two other interesting things pop up around me though. One guy is selling a 1.8L MSM engine with turbo, a 6spd, driveshaft, and torsen with half-axles for $2200 or so. From what I can see the turbo could get to the low 200s, however, I'd still need exhaust and an intercooler. I also don't know if it'd necessarily be a direct fit into a 1990. Another person is selling a complete kit with a gt2860 turbo, which would have literally everything I'd need for $2600. The guy is even throwing in a set of 640cc injectors. I'm thinking it'd be better to turbo my 1.6, rather than going with the MSM swap, but what do you guys think?

Saw that msm kit on Facebook. Real value of it is probably half of what he asks for.
You can get more vfm with a mkturbo kit.

you're joking? Here is street value of this msm stuff.
msm engine $1k
6spd $600
torsen with axles and shaft $1k
Msm turbo setup $500

I vote for the msm setup. It will upgrade the whole cars drivetrain. You will still need to add megasquirt

Did the MSM swap on a track car and it was great fun. Don't overspool the turbo though, they'll start grenading. Make sure your intercooler system is quality, and don't push for more than 12ish psi, which should be 200-220hp. Other than that, it's a '99 engine with a MUCH better coil setup, a bomb ass valve cover, an upgraded intake cam that alone is worth $200, and the turbo setup is actually well thought out and braced, never had issues with bolts stretching.

Handy little article with a few pictures, the car also has a build thread you can go through on CR.net or here:

https://www.gearboxmagazine.com/proj...l-inspire-you/

Excuse my misreading, middle of the night and all that. In that case well worth it.